Research On Continuum Robot For Ship Lock Underwater Space Detection

Continuum robot with flexible structure and flexible drive,is of good bending characteristics and environmental compatibility,and better suited to the situations where are many obstacles and unstructured space environment.For detection demands of ship lock underwater space,a kind of robot driven by pneumatic artificial muscle is realized by analyzing and designing.With the characteristics of the underwater lock of the ship lock analyzed,the overall structure scheme of the continuum robot with two flexible joints is established.Pneumatic artificial muscle is selected as the driving element.Based on the assumption of constant curvature,the analysis of the robot is carried out.Combined with the kinematics model,the parameters of the driving units and bending units are obtained,as a result a two-step continuum robot is established.Through analyzing and experimenting,and the error of the relationship between joint-space variables and driving-space variables is about 10%.The static performance of artificial muscle is tested by using isobaric test method,through muscle testing platform.Using the lsqcurvefit function to perform a nonlinear fit to represent its static properties.Based on the force balance in the normal direction,a flexible joint model of continuum robot is established,and the relationship between the robot bending angle and the tension of the driving line is deduced.The effect of friction on the robot bending angle is analyzed by using the friction model between the flexible cord and the rigid cylinder.Specialized test platform is established to measure the bending angle of a robot.And the results is that when the single muscle pressure is 0.62 MPa,robot's bending angle reaches 91.56?;when the impedance muscle pressure is 0.25 MPa and the main control muscle pressure is 0.74 MPa,the robot's bending angle reaches 62.74?.Through experiments with loads,it is verified that the bending angle is in a linear relationship with the value of the muscle pressure.Ship lock underwater virtual control platform is constructed,where manipulator can control the position and the bending posture of robot in virtual space.The robot underwater environment testing environment is constructed.The experiment shows that the robot's end camera can reach the detection position as expected to obtain the image to be detected in the water tank.